Calcium Carbonate
The short version
A white mineral pigment used as a colorant, anticaking agent, and calcium fortifier.
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Where it comes from
One of the most abundant minerals on earth, forming limestone, chalk, and marble. Food-grade calcium carbonate is mined and finely milled, or precipitated from purified calcium hydroxide solutions.
How it's used
Used as a white pigment in confectionery, an anticaking agent in dry mixes, a calcium fortifier in plant milks and cereals, and an antacid in pharmaceuticals.
Safety profile
No ADI required. Essential nutrient. Excessive intake (above 2 g/day calcium total) can cause constipation, kidney stones, or milk-alkali syndrome.
Physical & chemical properties
White, odorless, insoluble in water but reacts with acids to release CO2. Available in different particle sizes for different applications.
Regulation worldwide
Permitted globally with no quantitative limit for most food uses.
Educational information only. Not medical or dietary advice.